Microsoft’s March 2026 preview cumulative update, KB5079391, lets Windows 11 24H2 and 25H2 users toggle Smart App Control without a clean install — and adds support for monitors reporting refresh rates above 1000 Hz.
The optional release, part of Microsoft’s end-of-month preview schedule, bundles 29 changes but no security fixes. Smart App Control, previously a one-way door that required a full reinstall to enable, can now be switched on or off from
Settings > Windows Security > App & Browser Control > Smart App Control settings.
Display improvements include native USB4 monitor connections and better HDR reliability. Microsoft says the update also smooths x64 app behavior on ARM64 devices in Windows Recovery Environment and fixes Windows Hello fingerprint reliability on certain hardware.
Build numbers bump to 26100.8116 for 24H2 and 26200.8116 for 25H2. The package is available via Windows Update or the Microsoft Update Catalog; because it’s optional, users must click “Download and install” unless automatic previews are enabled.
Microsoft lists no known issues and notes the full changelog in its support bulletin.